1. Field of the Invention
This invention relates to a signal generating device operable and more particularly a signal generating device to generate vacuum and electrical signals in response to the degree of opening of a throttle valve for a vehicle engine.
2. Description of the Prior Art
The emission control system for a vehicle has various devices which are required to be operated in response to the opening degree of a throttle valve, and it is known to use vacuum and electrical signals as input signals to operate these devices. Conventionally, a vacuum signal, in response to the degree of opening of a throttle valve, is obtained by a vacuum signal generating device which is operatively connected to the throttle valve while the electrical signal in response to the degree of opening of the throttle valve is obtained by a potentiometer which is operatively connected to the throttle valve. This requires an independent vacuum signal generating device as well as a potentiometer, which is not cost expedient.